I've really enjoyed reading your answers; it has given me a lot to think about. I do have a lingering question. In a libertarian society, how would the police, fire and emergency services be funded and operated? Would I have to haggle with the various fire companies to find out who charges the least -- all while my house is burning down?
Of course not! Most insurance companies would probably require you to have a contract with a private fire station in order to get good rates. Most lenders would require insurance just as they do today.
Private ambulance providers already have subscribers in many municipalities. While subscribers pay little or nothing when they need emergency service, non-subscribers can get immediate service at higher (set) rates. Healthy people who don't anticipate many ambulance trips win by paying only when they use the service; the chronically ill pay less by becoming subscribers. Prices are kept low through competition. Everyone wins!
Private security could be, and already is, supplied in various ways as well. In some neighborhoods in San Francisco, residents voluntarily contribute to hiring a police officer to provide foot patrol. Reminderville, Ohio once hired Rural/Metro police, who decreased crime by 95% and cost by 50% just by instituting preventative measures.
For more detail, see Chapter 16 in my book, Healing Our World. The Advocates carries the 2003 edition, and the 1992 edition is available as a free download at Ruwart.com.